Report: Expiration of New START (Strategic Arms Reduction Treaty)

laure7549
8 hours ago
3 min read

Date: 11/02/2026

Summary

The New START Treaty has long been a cornerstone of strategic stability between the United States and Russia, placing firm limits on deployed nuclear weapons while providing verification measures that reduced uncertainty and mistrust. With the treaty now expired after its final extension, the world enters a new phase where legally binding constraints on the two largest nuclear arsenals are no longer in place. This article explores what New START achieved, why its expiration matters, and how its absence could reshape geopolitical relations and global security in the years ahead.

New Strategic Arms Reduction Treaty (New START)

The New Strategic Arms Reduction Treaty (New START) is a landmark arms control agreement between the United States and the Russian Federation that was designed to limit and bring transparency to the two largest nuclear arsenals in the world. Originally signed in 2010 and entering into force in February 2011, the treaty placed concrete limits on each side’s deployed strategic nuclear forces, including caps on 1,550 deployed strategic warheads, 700 deployed intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers, and a total of 800 deployed and non-deployed launchers, along with comprehensive verification measures such as data exchanges and on-site inspections to reduce the risk of misunderstanding or miscalculation.

New START was structured to remain in force for 10 years with an option for a single five-year extension, and in 2021 the United States and Russia agreed to exercise that extension, keeping the treaty legally in force through February 4, 2026. This extension preserved the treaty’s limits and monitoring mechanisms at a time when broader nuclear arms control efforts were under strain, and it reflected a shared interest -despite political tension- in maintaining some structure around strategic nuclear forces.

As of February 5, 2026, however, the extension period has officially expired, meaning the New START Treaty is no longer legally binding. Its lapse marks the first time in more than five decades that there are no formal, legally enforceable limits on the strategic nuclear arsenals of the United States and Russia. The expiration has sparked concern among diplomats, arms control experts, and international organizations, who warn that without a replacement framework the absence of binding limits could lead to a renewed arms race and decline in transparency between the world’s two principal nuclear powers. In September 2025, Russian leadership publicly offered to continue observing the established New START limits for an additional year after the treaty’s expiration, provided the United States agreed to reciprocal action, but no formal extension was agreed. Proposals for new arms control arrangements that might include other nuclear states such as China remain under discussion.

This integration of the extension into the New START story shows both the historic role of the treaty in stabilizing nuclear competition and the uncertainty now emerging as it lapses without a direct successor in place.

Looking ahead

Looking ahead, the expiration of New START removes one of the last remaining formal guardrails in US–Russia relations and risks accelerating a return to strategic uncertainty. Without binding limits and verification mechanisms, both sides may feel increased pressure to modernize and expand nuclear capabilities, not necessarily because of immediate intent to strike, but because reduced transparency fuels worst-case assumptions. This dynamic could further harden geopolitical relations, deepen mistrust, and increase the risk of miscalculation during periods of crisis, especially as conventional conflicts and cyber operations increasingly overlap with nuclear signaling. At the same time, the absence of a successor treaty may push global arms control into a more fragmented era, where nuclear stability depends less on bilateral agreements and more on shifting alliances, deterrence postures, and emerging technologies such as hypersonic weapons. In this context, nuclear arms control is likely to remain a key strategic issue—not only between Washington and Moscow, but also in broader debates involving China and other nuclear states, potentially reshaping diplomatic leverage and global security priorities for the coming decade.

Conclusion

The expiration of New START may look like a dramatic geopolitical rupture, but it does not automatically trigger a new nuclear arms race. The treaty’s end removes legally binding limits on deployed US and Russian strategic nuclear weapons and eliminates formal inspection and transparency mechanisms. That weakens predictability and reduces mutual confidence.

At the same time, expanding nuclear forces is not a switch that can simply be flipped. Uploading additional warheads or increasing deployments requires available delivery systems, industrial capacity, trained crews, and time. Russia’s defense industry is heavily burdened by the war in Ukraine, and the United States also faces procurement timelines and budget realities. Structural constraints still shape what is realistically possible.

The greater risk is therefore not an immediate surge in warhead numbers, but a gradual erosion of transparency and stability. Without agreed limits and verification, both sides may increasingly plan for worst-case scenarios, slowly intensifying strategic competition over the long term rather than overnight.